Myntra.com — exchange of kurta

Address:

400028

Delivered the kurta on 7th sept 2017 but i need a bigger size so i went through the procedure but its asking for change of address now i am confused as to which other address should i give. This is the first time i've placed order on myntra n it is not accepting my exchange request. I also called the delivery boy 7 he suggested to send acomplsin. Product detail - size m/qty 1
Code; 1870271
I want size l in the same address to be exchanged